Food safety officers up and down the country inspect the premises of just about anywhere that you can get food: schools, sandwich shops, pubs, hotels and bakeries.

In fact, the list of exceptions probably gives an even better indication of just how much they cover – only childminders, newsagents, chemist shops or "visitor centres selling tins of biscuits" don't need to be inspected for their hygiene standards.

So whether you're eating out or eating in, this is important information to know. Most places are fine to buy food from – the Food Standards Agency (FSA) passes 91% of food outlets – but what about the other 9%?

Anything less than a score of three out of five constitutes a fail. Businesses given ratings of 0 or 1 are those that need to make urgent or major improvements – but they're not closed down. That only happens if the food is so unsafe for the public to eat that there's an imminent risk to health.

So where are the chip shops, delicatessens and care homes that have failed their food inspections? They're all the red dots on the map below, which you can click on to see further detail. If you want to search for the postcode that you live in, try our interactive map here.

Though the FSA is responsible for food safety across the UK, there's a slightly different rating system in Scotland, which is why outlets there don't appear on our map.

Top of the (kitchen) table

Craigavon in Northern Ireland is the only local authority where 100% of food inspections resulted in a pass.

By contrast, Sutton and Bexley fall well short of the national average 91% pass rate – scoring just 68% and 66% respectively. You can also use our interactive map to spot regional trends. It shows that the biggest concentration of unhygienic food outlets is to be found in London.

Scores on the doors

Businesses aren't obliged to put their food ratings in their windows – although many that score well choose to do so with familiar stickers. A recent audit by the FSA found that more businesses are choosing to share their results.

Kay Chan and a food hygiene rating sign in the window of her restaurant Hong Kong Fusion in Norwich. Photograph: Graham Turner

Catriona Stewart, head of the food hygiene ratings team, said: "Many of us make spontaneous decisions about where to eat, so being able to see the rating on the door or in the window is important."

What do they inspect?

In its information pack for businesses, the FSA explains that it can inspect:> premises> the kinds of food made/prepared> how staff work> a business's food safety management system

And, if they feel it's necessary, they can:> inspect records> take samples and photographs of food> write to the business informally, asking them to put right any problems> detain or seize suspect foods

How often do they inspect?

The frequency of visits by the people in white coats depends partly on its hygiene record. Normally, food premises can expect a routine visit every six months or so but a complaint can bring an inspector at any time.

Note: Food inspections take place each and every day. We downloaded, checked, tabled and mapped these results a fortnight ago so they may have changed slightly since then. To double-check the results where you live, visit the FSA's website.